1. Field of the Invention
The present invention relates in general to scraper-chain conveyors for use in underground mineral mining installations and, more particularly, the invention is concerned with connection means and devices used to connect the individual channel sections or pans of the conveyor together.
2. Description of Prior Art
It is known to use a variety of devices to connect the adjacent ends of the channel sections of scraper-chain conveyors together. The main objective of these connection devices is to permit a certain limited degree of angular mobility between the ends of the channel sections in both horizontal and vertical senses while resisting tensile forces tending to draw the ends apart. The devices not only have to resist tensile forces but they also need to withstand other forces when the conveyor is shifted in the so-called `snaking` movement by rams which advance the conveyor over sections and when a winning machine passes along the conveyor. The inevitable uneveness in the floor of the mine working often aggravates the situation and results in increased stress in the components of the connecting devices. Hitherto, particularly satisfactory performances has been provided by using the so-called `dog-bone` type coupling which fits into shaped compartments in the end regions of the channel sections with a certain degree of free play. These known couplings are then retained in the compartments by releasable locking devices of various kinds. Typical prior art constructions are described in U.S. Pat. No. 4,157,751, German Patent Specifications Nos. 1 937 018 and 2 826 023 and German Utility Model No. 82 07 596.
The present invention seeks to provide an improved form of connection means of the known type.